City of El Centro Water Treatment Plant - Executive Summary |
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RISK MANAGEMENT PLAN - CITY OF EL CENTRO WATER TREATMENT PLANT The City of El Centro (CEC) has established a risk management plan according to EPA's Risk Management Program regulation (40 CFR Part 68) to enhance already existing safety and emergency response programs. CEC is extremely diligent in the handling of all chemicals and is very diligent about the safety of its employees and the neighboring Community. CEC staff is highly trained and utilizes modern equipment to monitor its facility to provide safeguards, while effectively and safely using chlorine for water treatment. Chlorine plays an important role in water treatment and water reclamation, enabling everyone to lead healthier lives. Accidental Release Prevention and Emergency Response Policies The CEC Water Treatment Plant has a long-standing commitment to worker and public safety. This commitment is demonstrated by the resources invested in accident prevention, such as training personnel and considering safety in the design, installation, operation, and maintenance of the Water Treatment Plant processes. CEC's policy is to implement reasonable controls to prevent foreseeable releases of regulated substances. The City of El Centro is in the process (target date = 10Sep99) of developing a facility-specific emergency response plan to handle potential emergency situations at the Water Treatment Plant. This plan will be designed to meet the following objectives: 1) To save lives 2) To minimize and avoid injuries 3) To protect the environment 4) To minimize property damage Key elements of the Emergency Response Plan will include: - A detailed Emergency Response Action Guide - Key phone numbers and contact points for City of El Centro personnel - Incident Command System (ICS) w/Unified Command interface - ICS position descriptions w/responsibilities - Vicinity and evacuation maps - Detailed task-by-task plans for: - Evacuation - Fire in a Process or Non-Process Area - Injuries - Threats/Civil Disorder - Wildland or Adjacent Property Fire - External Events (e.g., seismic) - Potential Imminent Danger to Personnel - Chemical Spill (e.g., caustic) - Chlorine Release - Off-Site Event Involving a Hazardous Material The City of El Centro Water Treatment Plant does not have a designated emergency response team; however, El Centro Fire Department specialists are trained and fully equipped to respond to hazardous material releases. The City of El Centro Water Treatment Plant Emergency Preparedness Coordinator will be maintaining an Emergency Response Plan for the facility. The Emergency Response Plan will provide the response protocols and notification procedures, evacuation routes, chlorine health hazards, and mitigation procedures, which will be implemented to respond effectively to emergency situations that may arise at the facility. This Plan will be reviewed and updated at least once per year to ensure compliance with PSM, RMP, and Ca lARP regulations. Stationary Source and Regulated Substance The chlorine system at the City of El Centro's Water Treatment Plant is used for the treatment of water from the supply canals prior to pumping into the City's water supply pipelines. The Chlorine Storage Room contains 8-10 one-ton chlorine cylinders, one chlorine detector (set @ 1 ppm), automatic switchover valves, one vacuum regulator, and one exhaust fan that is operated manually whenever personnel are present in the room. Two independent manifold systems (one active and the other kept on standby) are connected to a common header that feeds into the Chlorination Room. City of El Centro Operators use a monorail hoist to replace chlorine cylinders. The chlorine system is operated under vacuum conditions. Each one-ton cylinder is placed on a scale to allow City of El Centro Operators to plan ahead for ordering more chlorine and for planning the change-out procedure. Each container is positioned so that the valves are vertically aligned. A vacuum regulator is connected to the common header. A vacuum is created when process water is pumped through the injectors. This flow generates a vacuum (~1-3 in.-Hg), which opens the vacuum regulator. Upon loss of vacuum in the line from the one-ton cylinders, a diaphragm in the vacuum regulator will close, stopping any chlorine from escaping. Any chlorine in the piping upon loss of vacuum will be drawn through the chlorinators and into solution. The Chlorination Room contains 3 Wallace & Tiernan Vacuum-Operated Chlorinators, one chlorine detector (set @ 1 ppm), and one exhaust fan that is operated continuously. Scrubbers are not installed in any of the Water Treatment Plant rooms; however, each chlorine detector triggers an alarm that will alert the Operators to a high ambient chlorine concentration in either the Chlorination Room or in the Chlorine Storage Room. The maximum quantity of chlorine that can be stored on site is 16,000-20,000 pounds (8-10 on e-ton cylinders). Hazard Assessment Summary Worst-Case Release Scenario Results Summary Scenario Description: Release of the maximum quantity of chlorine that can be stored in the largest container - 2,000 pounds in 10 minutes. The chlorine cylinders are located in a building; therefore, this passive mitigation measure was incorporated in the calculations. The most pessimistic meteorological conditions were used, as specified by regulation. RMP*Comp was used to determine the maximum downwind endpoint distance to 3 ppm. The result shows that off-site areas may be affected. Alternative Release Scenario Results Summary Scenario Description: A release of chlorine gas from 1/4-inch diameter leak until the chlorine cylinder is empty (2,000 pounds). The chlorine cylinders are located in a building; therefore, this passive mitigation measure was incorporated in the calculations. Scrubbers are not installed at the City of El Centro Water Treatment Plant; therefore, active mitigation c redit is not taken for the alternative release scenario. The meteorological conditions specified by regulation for alternative release scenarios were used. RMP*Comp was used to determine the maximum downwind endpoint distance to 3 ppm. The downwind distance for this alternative release scenario is significantly less than that for the worst-case scenario. Although off-site areas may also be affected for this alternative release scenario, the maximum endpoint distance for the alternative release scenario is just beyond the City of El Centro Water Treatment Plant perimeter. Risk Considerations Although the storage and use of chlorine has inherent potential risks, and worst-case release scenarios can potentially reach the Community; the City of El Centro Water Treatment Plant has recognized these potential risks and structured its safety programs to make this type of event non-credible. In addition to the use of conservative analysis assumptions that overpredict the effects of a pote ntial release, other characteristics of the facility and site serve to minimize the potential risks associated with a chlorine release: - Valves to permit isolation of the process exist. - Personal Protective Equipment (PPE) (e.g., protective clothing, self-contained breathing apparatus) is used by plant personnel. - The history of the CEC Water Treatment Plant (i.e., no RMP-applicable chlorine releases) reflects the adequacy of the design and diligence of the plant staff in safely operating the Chlorine System. Accidental Release Prevention Program and Chemical-Specific Prevention Steps The City of El Centro will have a Process Safety Management program in place to manage the handling of chlorine. In addition, common industry standards, policies, and procedures are currently utilized to ensure safe practices are being performed. This includes common practices outlined by the Chlorine Institute. In addition to the Management Programs, there are chlorine leak detectors situated in all rooms that contain chlorine (2 total). In the event of a chlorine gas leak, the detectors relay a signal that activates a horn and a light outside the room where chlorine has been detected. In addition, the alarm is displayed on the control system panel. At 1 ppm, the alarm signal is directly wired to alert the El Centro Police Department Dispatch. Five-Year Accident History There have been no RMP-applicable releases of chlorine at the City of El Centro Water Treatment Plant in the past five years. Emergency Response Program See above discussion in "Accidental Release Prevention and Emergency Response Policies". Planned Changes to Improve Safety Several studies will be conducted prior to September 10, 1999 to examine mitigation measures to improve safety at the City of El Centro Water Treatment Plant. These studies include the following: Process Safety Management (PSM), Process Hazard Analysis (PHA), and Seismic Assessment. Any recommendations precipitating from t hese studies will be addressed by December, 31 1999. |